The present invention relates to a dosing device for liquids with which several, preferably two, liquids can be brought together in precisely measured quantities and mixed together.
The known dosing device for dispensing several liquids, which forms the basis of this invention (Published European Application 0 448 394), comprises at least two cylinder-piston arrangements connected by one suction valve and one suction line each to an external liquid-reservoir and to a discharge device with a mixing chamber and discharge aperture via a discharge line with discharge valve. All the components of the dosing device are interconnected and thus, if the dosing device is accommodated in a housing, said components are arranged in said housing, while the liquids to be mixed together, such as a drink concentrate and water, are fed via admission lines from liquid-reservoirs outside the housing. In this known dosing device, the diameters of the cylinder-piston arrangements vary widely so that with one and the same piston stroke, different quantities of liquids can be dispensed, for example at a ratio of 1:3. Furthermore it is also possible to modify the lever mechanism driven by a single mutual drive element, namely a hand lever of a drive device, such that the pistons are moved with different lever arms, in which case different piston strokes are achieved with one and the same drive movement of the drive element. In this way too, the dispensed ratio of the liquids can be altered.
The above mentioned dosing device for liquids, known in the art, by means of which device several liquids can be brought together in precisely measured quantities and mixed, can still be improved from the point of view of handling. Furthermore, in particular for specific medical, pharmaceutical and chemical applications it would be more useful if this dosing device were a device, which, on the whole, could be handled as a closed unit. Moreover, but related to the above, it would be desirable to shift the dispensed ratio of the different liquids to significantly higher levels and to make said ratio flexible and/or adjustable. Finally, again of particular significance in the fields of medical, pharmaceutical and chemical applications, it would be desirable in such a dosing device, if the discharge device could be cleared of liquid residues in a targeted way.
According to the present invention, the cylinder-piston arrangements of the dosing device are not connected to the respective liquid-reservoirs via admission lines, but instead, these cylinder-piston arrangements are designed more or less as commercially available bottle-top dispensers (see e.g. published German applications 197 02 773 and DE 197 02 778). Integrated in the bottle-top mechanism, which usually is a screw-on mechanism, of a bottle-top dispenser, and also integrated in a dispensing arm jutting out from said bottle-top dispenser, are the suction valves and the discharge valves as well as the suction lines and the discharge lines. This is a compact design which has been well proven in practical applications. Each of the bottle-top dispensers is firmly attached in the housing. Thus, according to the invention, the bottle-top dispensers are used atypically, namely firmly attached in the housing, while the liquid-reservoir bottles are attached to the fixed bottle-top dispensers by means of the bottle-top mechanism, in particular screwed on. In this way there is no need for external admission lines and external liquid-reservoirs. This is a construction that results in an overall compact design of the dispensing device, where applicable in a closed housing. This is very useful, in particular for the above-mentioned applications in the medical, pharmaceutical and chemical sectors.
The possibility of designing a dosing device with which a large dispensing ratio is to be achieved exists in making the effective lever arms for activating the pistons of the cylinder-piston arrangements very differently. One and the same drive movement of the drive device then leads to very different working strokes of the pistons. If the cylinder-piston arrangements are arranged side-by-side in relation to the principal plane of the housing of the dosing device, then the desired significantly different lever transmission can be achieved by way of an operating lever located on one side, and by the cylinder-piston arrangements being sufficiently spaced apart from each other. While the housing is wide in this arrangement, it is not excessively deep.
The blow-out device makes it possible to clear the liquids to be dispensed from the discharge device, either automatically after each dispensing procedure or optionally only as deemed necessary. In this way it is possible to avoid undesirable chemical processes in the case of liquid components remaining in the discharge device for an extended period of time.
Of particular significance is the use of a dosing device according to the invention for mutual dispensing of different components of a medically effective disinfectant, in particular a temporarily stable peroxide-alcohol mixture.